21089671 has 2 divisors, whose sum is σ = 21089672. Its totient is φ = 21089670.

The previous prime is 21089659. The next prime is 21089681. The reversal of 21089671 is 17698012.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21089671 - 2¹¹ = 21087623 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21089611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10544835 + 10544836.

It is an arithmetic number, because the mean of its divisors is an integer number (10544836).

Almost surely, 2^21089671 is an apocalyptic number.

21089671 is a deficient number, since it is larger than the sum of its proper divisors (1).

21089671 is an equidigital number, since it uses as much as digits as its factorization.

21089671 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6048, while the sum is 34.

The square root of 21089671 is about 4592.3491809748. The cubic root of 21089671 is about 276.2845512772.

The spelling of 21089671 in words is "twenty-one million, eighty-nine thousand, six hundred seventy-one".